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[PATCH] md: tidy up raid5/6 hash table code

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- replace open-coded hash chain with hlist macros

- Fix hash-table size at one page - it is already quite generous, so there
  will never be a need to use multiple pages, so no need for __get_free_pages

No functional change.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
NeilBrown 2006-01-06 00:20:33 -08:00 • committed by Linus Torvalds
parent 9ffae0cf3e
commit fccddba060
3 changed files with 33 additions and 57 deletions
Download patch file Download diff file Expand all files Collapse all files

40
drivers/md/raid5.c
View file

@ -35,12 +35,10 @@
#define STRIPE_SHIFT (PAGE_SHIFT - 9) #define STRIPE_SHIFT (PAGE_SHIFT - 9)
#define STRIPE_SECTORS (STRIPE_SIZE>>9) #define STRIPE_SECTORS (STRIPE_SIZE>>9)
#define IO_THRESHOLD 1 #define IO_THRESHOLD 1
#define HASH_PAGES 1 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
#define HASH_PAGES_ORDER 0
#define NR_HASH (HASH_PAGES * PAGE_SIZE / sizeof(struct stripe_head *))
#define HASH_MASK (NR_HASH - 1) #define HASH_MASK (NR_HASH - 1)
#define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]) #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
/* bio's attached to a stripe+device for I/O are linked together in bi_sector /* bio's attached to a stripe+device for I/O are linked together in bi_sector
* order without overlap. There may be several bio's per stripe+device, and * order without overlap. There may be several bio's per stripe+device, and
@ -113,29 +111,21 @@ static void release_stripe(struct stripe_head *sh)
spin_unlock_irqrestore(&conf->device_lock, flags); spin_unlock_irqrestore(&conf->device_lock, flags);
} }
static void remove_hash(struct stripe_head *sh) static inline void remove_hash(struct stripe_head *sh)
{ {
PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector);
if (sh->hash_pprev) { hlist_del_init(&sh->hash);
if (sh->hash_next)
sh->hash_next->hash_pprev = sh->hash_pprev;
*sh->hash_pprev = sh->hash_next;
sh->hash_pprev = NULL;
}
} }
static __inline__ void insert_hash(raid5_conf_t *conf, struct stripe_head *sh) static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
{ {
struct stripe_head **shp = &stripe_hash(conf, sh->sector); struct hlist_head *hp = stripe_hash(conf, sh->sector);
PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector);
CHECK_DEVLOCK(); CHECK_DEVLOCK();
if ((sh->hash_next = *shp) != NULL) hlist_add_head(&sh->hash, hp);
(*shp)->hash_pprev = &sh->hash_next;
*shp = sh;
sh->hash_pprev = shp;
} }
@ -228,10 +218,11 @@ static inline void init_stripe(struct stripe_head *sh, sector_t sector, int pd_i
static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector) static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector)
{ {
struct stripe_head *sh; struct stripe_head *sh;
struct hlist_node *hn;
CHECK_DEVLOCK(); CHECK_DEVLOCK();
PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector);
for (sh = stripe_hash(conf, sector); sh; sh = sh->hash_next) hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
if (sh->sector == sector) if (sh->sector == sector)
return sh; return sh;
PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector);
@ -1835,9 +1826,8 @@ static int run(mddev_t *mddev)
conf->mddev = mddev; conf->mddev = mddev;
if ((conf->stripe_hashtbl = (struct stripe_head **) __get_free_pages(GFP_ATOMIC, HASH_PAGES_ORDER)) == NULL) if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
goto abort; goto abort;
memset(conf->stripe_hashtbl, 0, HASH_PAGES * PAGE_SIZE);
spin_lock_init(&conf->device_lock); spin_lock_init(&conf->device_lock);
init_waitqueue_head(&conf->wait_for_stripe); init_waitqueue_head(&conf->wait_for_stripe);
@ -1972,9 +1962,7 @@ static int run(mddev_t *mddev)
abort: abort:
if (conf) { if (conf) {
print_raid5_conf(conf); print_raid5_conf(conf);
if (conf->stripe_hashtbl) kfree(conf->stripe_hashtbl);
free_pages((unsigned long) conf->stripe_hashtbl,
HASH_PAGES_ORDER);
kfree(conf); kfree(conf);
} }
mddev->private = NULL; mddev->private = NULL;
@ -1991,7 +1979,7 @@ static int stop(mddev_t *mddev)
md_unregister_thread(mddev->thread); md_unregister_thread(mddev->thread);
mddev->thread = NULL; mddev->thread = NULL;
shrink_stripes(conf); shrink_stripes(conf);
free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER); kfree(conf->stripe_hashtbl);
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
kfree(conf); kfree(conf);
@ -2019,12 +2007,12 @@ static void print_sh (struct stripe_head *sh)
static void printall (raid5_conf_t *conf) static void printall (raid5_conf_t *conf)
{ {
struct stripe_head *sh; struct stripe_head *sh;
struct hlist_node *hn;
int i; int i;
spin_lock_irq(&conf->device_lock); spin_lock_irq(&conf->device_lock);
for (i = 0; i < NR_HASH; i++) { for (i = 0; i < NR_HASH; i++) {
sh = conf->stripe_hashtbl[i]; hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
for (; sh; sh = sh->hash_next) {
if (sh->raid_conf != conf) if (sh->raid_conf != conf)
continue; continue;
print_sh(sh); print_sh(sh);

42
drivers/md/raid6main.c
View file

@ -40,12 +40,10 @@
#define STRIPE_SHIFT (PAGE_SHIFT - 9) #define STRIPE_SHIFT (PAGE_SHIFT - 9)
#define STRIPE_SECTORS (STRIPE_SIZE>>9) #define STRIPE_SECTORS (STRIPE_SIZE>>9)
#define IO_THRESHOLD 1 #define IO_THRESHOLD 1
#define HASH_PAGES 1 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
#define HASH_PAGES_ORDER 0
#define NR_HASH (HASH_PAGES * PAGE_SIZE / sizeof(struct stripe_head *))
#define HASH_MASK (NR_HASH - 1) #define HASH_MASK (NR_HASH - 1)
#define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]) #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
/* bio's attached to a stripe+device for I/O are linked together in bi_sector /* bio's attached to a stripe+device for I/O are linked together in bi_sector
* order without overlap. There may be several bio's per stripe+device, and * order without overlap. There may be several bio's per stripe+device, and
@ -132,29 +130,21 @@ static void release_stripe(struct stripe_head *sh)
spin_unlock_irqrestore(&conf->device_lock, flags); spin_unlock_irqrestore(&conf->device_lock, flags);
} }
static void remove_hash(struct stripe_head *sh) static inline void remove_hash(struct stripe_head *sh)
{ {
PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector); PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector);
if (sh->hash_pprev) { hlist_del_init(&sh->hash);
if (sh->hash_next)
sh->hash_next->hash_pprev = sh->hash_pprev;
*sh->hash_pprev = sh->hash_next;
sh->hash_pprev = NULL;
}
} }
static __inline__ void insert_hash(raid6_conf_t *conf, struct stripe_head *sh) static inline void insert_hash(raid6_conf_t *conf, struct stripe_head *sh)
{ {
struct stripe_head **shp = &stripe_hash(conf, sh->sector); struct hlist_head *hp = stripe_hash(conf, sh->sector);
PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector); PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector);
CHECK_DEVLOCK(); CHECK_DEVLOCK();
if ((sh->hash_next = *shp) != NULL) hlist_add_head(&sh->hash, hp);
(*shp)->hash_pprev = &sh->hash_next;
*shp = sh;
sh->hash_pprev = shp;
} }
@ -247,10 +237,11 @@ static inline void init_stripe(struct stripe_head *sh, sector_t sector, int pd_i
static struct stripe_head *__find_stripe(raid6_conf_t *conf, sector_t sector) static struct stripe_head *__find_stripe(raid6_conf_t *conf, sector_t sector)
{ {
struct stripe_head *sh; struct stripe_head *sh;
struct hlist_node *hn;
CHECK_DEVLOCK(); CHECK_DEVLOCK();
PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector); PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector);
for (sh = stripe_hash(conf, sector); sh; sh = sh->hash_next) hlist_for_each_entry (sh, hn, stripe_hash(conf, sector), hash)
if (sh->sector == sector) if (sh->sector == sector)
return sh; return sh;
PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector); PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector);
@ -1931,17 +1922,15 @@ static int run(mddev_t *mddev)
return -EIO; return -EIO;
} }
mddev->private = kmalloc (sizeof (raid6_conf_t) mddev->private = kzalloc(sizeof (raid6_conf_t)
+ mddev->raid_disks * sizeof(struct disk_info), + mddev->raid_disks * sizeof(struct disk_info),
GFP_KERNEL); GFP_KERNEL);
if ((conf = mddev->private) == NULL) if ((conf = mddev->private) == NULL)
goto abort; goto abort;
memset (conf, 0, sizeof (*conf) + mddev->raid_disks * sizeof(struct disk_info) );
conf->mddev = mddev; conf->mddev = mddev;
if ((conf->stripe_hashtbl = (struct stripe_head **) __get_free_pages(GFP_ATOMIC, HASH_PAGES_ORDER)) == NULL) if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
goto abort; goto abort;
memset(conf->stripe_hashtbl, 0, HASH_PAGES * PAGE_SIZE);
conf->spare_page = alloc_page(GFP_KERNEL); conf->spare_page = alloc_page(GFP_KERNEL);
if (!conf->spare_page) if (!conf->spare_page)
@ -2085,9 +2074,7 @@ abort:
print_raid6_conf(conf); print_raid6_conf(conf);
if (conf->spare_page) if (conf->spare_page)
put_page(conf->spare_page); put_page(conf->spare_page);
if (conf->stripe_hashtbl) kfree(conf->stripe_hashtbl);
free_pages((unsigned long) conf->stripe_hashtbl,
HASH_PAGES_ORDER);
kfree(conf); kfree(conf);
} }
mddev->private = NULL; mddev->private = NULL;
@ -2104,7 +2091,7 @@ static int stop (mddev_t *mddev)
md_unregister_thread(mddev->thread); md_unregister_thread(mddev->thread);
mddev->thread = NULL; mddev->thread = NULL;
shrink_stripes(conf); shrink_stripes(conf);
free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER); kfree(conf->stripe_hashtbl);
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
kfree(conf); kfree(conf);
mddev->private = NULL; mddev->private = NULL;
@ -2131,12 +2118,13 @@ static void print_sh (struct seq_file *seq, struct stripe_head *sh)
static void printall (struct seq_file *seq, raid6_conf_t *conf) static void printall (struct seq_file *seq, raid6_conf_t *conf)
{ {
struct stripe_head *sh; struct stripe_head *sh;
struct hlist_node *hn;
int i; int i;
spin_lock_irq(&conf->device_lock); spin_lock_irq(&conf->device_lock);
for (i = 0; i < NR_HASH; i++) { for (i = 0; i < NR_HASH; i++) {
sh = conf->stripe_hashtbl[i]; sh = conf->stripe_hashtbl[i];
for (; sh; sh = sh->hash_next) { hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
if (sh->raid_conf != conf) if (sh->raid_conf != conf)
continue; continue;
print_sh(seq, sh); print_sh(seq, sh);

4
include/linux/raid/raid5.h
View file

@ -126,7 +126,7 @@
*/ */
struct stripe_head { struct stripe_head {
struct stripe_head *hash_next, **hash_pprev; /* hash pointers */ struct hlist_node hash;
struct list_head lru; /* inactive_list or handle_list */ struct list_head lru; /* inactive_list or handle_list */
struct raid5_private_data *raid_conf; struct raid5_private_data *raid_conf;
sector_t sector; /* sector of this row */ sector_t sector; /* sector of this row */
@ -204,7 +204,7 @@ struct disk_info {
}; };
struct raid5_private_data { struct raid5_private_data {
struct stripe_head **stripe_hashtbl; struct hlist_head *stripe_hashtbl;
mddev_t *mddev; mddev_t *mddev;
struct disk_info *spare; struct disk_info *spare;
int chunk_size, level, algorithm; int chunk_size, level, algorithm;